VW Up Power Loss + Limp Mode Points to Throttle Sensor

Had similar symptoms on a Polo TSI last year. The engine idling issues and power loss turned out to be a faulty electronic throttle body, which connects to the accelerator pedal module. The air intake and fuel delivery were fine, but the throttle position sensor was sending incorrect signals to the ECU. The main symptoms matched exactly: poor engine idling, unusual power cuts, and response delay when pressing the accelerator. The car would occasionally go into limp mode as a safety measure. These issues indicate a serious electronic malfunction that affects both fuel efficiency and engine performance. The repair required replacing the complete throttle body unit since the electronics inside were defective. Not a quick fix, the shop needed to program and calibrate the new unit to work with the ECU. Worth getting diagnosed properly as driving with these symptoms could cause additional engine damage. Keep in mind throttle bodies can fail from normal wear, especially around this mileage. The check engine light storing specific fault codes will help pinpoint if this is indeed your issue.

Thanks for sharing your experience. My symptoms sound identical to what you described with the throttle body issue. Did you happen to remember the replacement cost for the complete unit including labor? Also curious if youve had any similar problems pop up since getting it fixed last year. Want to budget properly since these electronic components can be expensive.

Just wanted to follow up since getting the repair done. The throttle valve was indeed defective, causing those exact engine idling and response delay issues we discussed. Total cost came to 265€ for replacing the accelerator pedal module due to faulty electronics inside. The air flow and engine performance returned to normal immediately after the fix. No check engine light or power loss problems have occurred since the repair was completed. The shop did a thorough job programming and calibrating the new unit to work with the ECU. Looking back, it was worth addressing quickly before it could cause additional engine damage. These electronic throttle components are critical for proper engine operation, and the symptoms we both experienced are classic indicators of failure. If your symptoms match what I described, you should be looking at similar repair costs. Just make sure they test the complete throttle system to confirm the exact component that needs replacement.

Thanks everyone for the help. Just got back from the mechanic and wanted to share what happened. The throttle body was indeed the culprit, causing all those engine idling problems. Ended up paying 290€ for parts and labor, slightly more than expected but still reasonable. The mechanic found the throttle position sensor was completely shot, which explained the unusual power loss and response delay issues. They installed a new unit and properly calibrated it to the ECU. The difference in performance was immediate, no more limp mode episodes or rough running. Fuel efficiency has improved noticeably since the repair. The engine runs smooth now, especially at idle. Really glad I addressed this before it led to bigger problems. For anyone else seeing similar symptoms, definitely worth getting it checked out sooner rather than later.